Over the past few weeks I have been working on mapping a cemetery in a Geographic Information System (GIS) as both part of a class and part of my own research. I received a number of question and comments on Twitter from readers asking how this was done and what exactly I was doing. What I want to share today is a little background on doing spatial analyses of cemeteries, and some projects that have already been completed using GIS.
First, a little background on GIS and spatial analysis. A geographic information system (GIS) lets us create spatial maps in order to visualize, analyze, and interpret data to reveal patterns. Basically, we put spatial data (data with longitude and latitude, or other geographic coordinates) into the computer program, and it allows us to assess this data. Within this program, we can also digitize maps and give them spatial data. For example, I took a map of Anglo-Saxon burials, placed it onto a spatially located map in the program, and then digitized each burial into specific points. Another way of inputting data is with GPS coordinates. During my undergrad, my senior thesis involved taking GPS coordinates of historic grave markers, putting them into the GIS and assigning information to them. The goal of both projects is to determine why the cemetery looks the way it does- is it organized into neat rows? Or family groups? Or was its growth random and natural? The analytical tools in the program allow us to assess distance, spatial relationships, location patterns or other information. It can be used to understand space use in both historic cemeteries and modern ones.
There are a number of ancient and historic projects using GIS to interpret mortuary sites. Sayer and Wienhold (2012) argue that analysis of Anglo-Saxon cemeteries have been primarily based on the rich material goods found at them, but the spatial assessment is just as important. GIS can be used to test different types of relationships than traditional statistical methods or by simple visual assessment. Macroscopic or simple visual analysis has argued that cemeteries appear to cluster around multiple foci and these may be family clusters. For their investigation, they use four cemeteries that date from the 6th to 7th centuries CE. They assess burials using Ripley’s K function which measures clustering or segregation, and kernel density which creates a visual of holes and foci. The variables selected are presence of grave furnishings and chronology. They found that there were a number of large clusters present at each cemetery, some loose and some tight. The addition of chronology was important as the clustering only became apparent when it was accounted for. They argue that these cemeteries have plots that are made for large multi-vocational households and there is status differentiation within them.
Another historic analysis was done by Herrmann (2002) used GIS to analyze cave burials in Honduras. Understanding the deposition of bodies within caves can be difficult, and interpretations range from convenience to symbolic purposes. From the site of Cueva de las Arañas, he was able to use digital images of the cave and an overall map to create a digital map with every bone. Each bone was assigned data about its area (axial, appendicular, cranial), side (left or right), and type of bone. He argues that GIS allows analysis of the context and remains within the lab. It also allows for ossuaries (areas where to be mapped in a coherent manner, allowing singular types of bones to be selected and analyzed. By creating a digital map of the cave, they can better visualize the distribution of bones and better interpret them. Based on the analysis of distribution of crania, tibia and femora, he concludes that it was likely that individuals were brought into the cave after already having decomposed and were placed as bundles within the cave. This is evidenced by the presence of single pairs of the long bones and a single crania in these piles found throughout the save.
For one more, check out my post on “Landscapes of Death” which discusses a really cool project to determine whether the location of burial sites around Lake Titicaca was random or had meaning.
GIS is also used in more modern cemeteries to map location of the deceased and to aid with cemetery organization. The Old Cohansey Baptist Cemetery, dating to the 17th and 18th centuries, in New Jersey was mapped using GPS and GIS in order to create a record of the cemetery (Mollick 2005). The cemetery lacked any historical information, and there were no maps. They used coordinates of each grave marker, and attached data on the individuals they could glean from the markers such as name, age, years, sex, and style of marker. Not only did this create a map of the cemetery and aid in its historic preservation, it allowed for analyses of the cemetery to understand distribution of grave marker types, genealogical relationships by identifying family plots as well as age and sex distributions. Most importantly, the project collected information on preservation in order to determine which areas of the cemetery were in most need of conservation and renewal. Another example of this is the Riverside Cemetery in North Carolina which was mapped using GIS to preserve information and protect the heritage of this historic location.
A very modern example is that of the City of Waukesha’s Prairie Home Cemetery GIS. This was developed using a Cemetery Information Management System (CIMS), a customized GIS specifically for cemetery management. The GIS allows for users to search for specific burial plots of individuals and gain information about date of burial, age, the funeral home, and the specific location in the cemetery. You can also see burial plots that are reserved for individuals, and ones that are open and not reserved. What will be great, is that as this cemetery ages and fills up (which it is pretty close to already) we will already have a GIS in place for historical research. (See screenshot below: red= current burial, blue= restricted burial, orange= sold, green= open)
GIS is a great tool for doing spatial analyses of mortuary sites, both past and present. Honestly, it’s one of the best skills I acquired during my undergrad years and one that has become pivotal to my dissertation research. If you know of any good GIS projects, ancient, historic or modern, please let me know and I will add them to this list!
Sayer, D., & Wienhold, M. (2012). A GIS-Investigation of Four Early Anglo-Saxon Cemeteries: Ripley’s K-function Analysis of Spatial Groupings Amongst Graves Social Science Computer Review, 31 (1), 71-89 DOI: 10.1177/0894439312453276
Herrmann, Nicholas (2002). GIS Applied to Bioarchaeology Journal of Cave and Karst Studies, 64 (1), 17-22
Mollick, S. 2005. Mapping the Dead. Presentation at the ESRI Conference. Paper Available in Electronic Format. http://proceedings.esri.com/library/userconf/proc05/papers/pap1008.pdf